As a content distribution technology utilizing hypertext transfer protocol (HTTP), moving picture experts group—dynamic adaptive streaming over HTTP (MPEG-DASH) has been standardized in recent years (for example, see Non-patent Document 1). This MPEG-DASH adopts an adaptive bitrate streaming (ABS) technology which stores a plurality of encoded data in a content server as data representing identical content by different bitrates, and allows a client to select one of the plurality of encoded data in accordance with a network band and reproduce the selected data.
Incidentally, it has been considered to adaptively select a partial image corresponding to a part of an entire image and distribute the selected partial image, rather than distribute the entire image. For example, it has been considered to distribute a partial image selected from an entire image by an image data receiving terminal, and control a size of a partial image to be distributed in accordance with performance of a terminal (such as processing capability of CPU and size of display), a transmission channel, a server loading state, and other conditions.
In addition, it has been considered to adopt layer encoding to efficiently encode an image constituted by a plurality of layers by using prediction between layers or the like, for example.